This invention relates to a liquid jetting head for ejecting a liquid droplet from a nozzle orifice by causing pressure fluctuation to occur in liquid in a pressure chamber as a piezoelectric vibrator becomes deformed.
Liquid jetting heads each for ejecting a liquid droplet from a nozzle orifice by causing pressure fluctuation to occur in liquid in a pressure chamber include a recording head, a liquid crystal jetting head, a color material jetting head, and the like, for example. The recording head is installed in an image recording apparatus such as a printer or a plotter for ejecting ink liquid as ink droplets. The liquid crystal jetting head is used with a display manufacturing apparatus for manufacturing liquid crystal displays. In the display manufacturing apparatus, a liquid crystal ejected from the liquid crystal jetting head is poured into a predetermined grid of a display substrate having a large number of grids. The color material jetting head is used with a filter manufacturing apparatus for manufacturing a color filter, and ejects a color material onto the surface of a filter substrate.
Various types of liquid jetting heads are available, one of which is a liquid jetting head for ejecting liquid droplets by deflecting and deforming piezoelectric vibrators formed on the surface of a vibration plate. This liquid jetting head is made up of an actuator unit including pressure chambers and piezoelectric vibrators and a flow passage unit including nozzle orifices and a common liquid reservoir, for example. In the liquid jetting head, a piezoelectric vibrator on the vibration plate is deformed, whereby the volume of the corresponding pressure chamber is changed for causing pressure fluctuation to occur in liquid stored in the pressure chamber. Using the pressure fluctuation, a liquid droplet is ejected from the corresponding nozzle orifice. For example, the pressure chamber is contracted, whereby liquid is pressurized for pushing out the liquid from the nozzle orifice.
By the way, there is a strong demand for miniaturizing such a liquid jetting head, because the range of uses of the liquid jetting head can be increased as the liquid jetting head is miniaturized. The actuator units are produced, for example, as ceramics are baked. Thus, as the actuator unit is miniaturized, the number of actuator units produced for each lot (for example, from one ceramic sheet) can be increased, leading to cost reduction.